Final Fantasy XIV: the "Kupo Astrology" Mog Mog Collection opens September 9 — the uolon horn requires 100 memory crystals and 10 vouchers, one per week

Square Enix released the announcement of the Mog Mog Collection "Kupo Astronomy - Part 1" on Wednesday, September 2, 2026 at 11:30 am (Paris time). The event opens in Final Fantasy XIV Online on Wednesday, September 9, 2026 at 10:00 am, the day after the 7.56 update, and closes on Monday, October 19, 2026 at 4:59 pm, Paris time — that is 40 days and 7 hours. The duration is our subtraction: the publisher only releases the two boundary dates.

This edition steps outside the usual framework: "In honor of the new expansion 'Evercold', this special edition of the Mog Mog Collection will be split into two parts and will feature a new reward: the uolon horn!", writes the French Lodestone. This mount is the only item in the catalog to require two currencies, and the second is capped at one copy per week: it locks down the date by which you'll be able to exchange it, regardless of how much time you spend playing.

Two currencies for a single mount

The memory crystals are collected in a loop: no limit is announced. The uolon horn credits have only two sources, and the publisher lists both: "the Mog Mog challenge can only be completed once over the entire duration of the event: You will receive 5 uolon horn credits by completing the Mog Mog challenge, and 1 uolon horn credit by completing the weekly Mog challenge each week."

Five credits earned once and for all, then one per week: reaching ten means succeeding at the weekly Mog challenge five times. This is our arithmetic, not data from the publisher — but it leaves no room for interpretation.

The schedule: the mount cannot be exchanged before October 6

The reset schedule, however, is published: "The weekly Mog challenge changes every Tuesday at 9:00 am winter time, and every Tuesday at 10:00 am summer time (Paris time)." European summer time runs until Sunday, October 25, 2026, beyond the close of Part 1: over the entire duration of the event, the appointment is therefore Tuesday at 10:00 am. This is our reading of the civil calendar, the publisher does not make this conversion on your behalf.

This breakdown is our own: Square Enix gives the reset day and the two boundary dates, never the number of weeks. Two conclusions follow. A player who checks off everything from the very opening cannot exchange the uolon horn before Tuesday, October 6, 2026 at 10:00 am, nearly four weeks after the start. And the margin is limited to one week: miss two weekly Mog challenges, and the counter caps at nine.

The date to remember, then, is not September 19, it's Tuesday, September 22, 2026 at 10:00 AM. Anyone who hasn't completed their first Weekly Mog Challenge before that reset only has four windows left.

One caveat, and it's a serious one: the publisher does not state anywhere whether this challenge is available as of September 9, in a game week opened the day before with 7.56, or only from the September 15 reset onward. In this second scenario, only five windows remain and there's no margin left at all. Taking on the first challenge as soon as it opens settles the question at no cost.

What Part 2 keeps, and what it doesn't

The official site addresses this case: the Uolon Horn and its currencies "will once again be obtainable during the next edition," and "the currencies obtained in Part 1 will be usable in Part 2." Don't stretch that statement: what's guaranteed to carry over is the currency. The announcement also warns that "the rewards as well as the memory crystals to exchange will not be the same during the first and second parts." So nothing indicates that your 100 Unusual Astronomical Memory Crystals I will go toward the same purchase afterward, and Square Enix has published neither the date for Part 2 nor the price the mount will have there.

Four sources of memory crystals, and three cases where they don't drop

Regular content first: the activities in question "are marked with a Mog icon in the Duty Finder." Then weekly content, "one objective per week among regular content"; the Weekly Mog Challenge, which offers "two objectives" of which only one must be completed; and the Mog Mog Challenge, a single one, with "a special objective." New to this edition, memory crystals also drop "during all ocean fishing voyages, as well as in the Gold Saucer's GATEs." Fishing comes with a numerical requirement, "a score of 2000 points" per voyage.

Three situations cancel the reward, and two of them are the reflexes of a hurried player:

• incursion missions carried out with your Grand Company squadron yield nothing;
• the Support system doesn't either;
• the "Unrestricted Party" option in the Duty Finder only yields memory crystals "if you also enable the 'Level Sync' option."

One point remains open, and it's worth a warning: no quantity per piece of content has been published. It is therefore impossible to calculate the number of duties needed to gather 100 memory crystals — no estimate will be able to rely on an official source before launch.

The exchange list: 29 items, from 50 down to 1 memory crystal

Adding up the price column gives 624 Memory Crystals for one of each of the 29 items, plus the 100 for the Uolon Horn, for a total of 724. This is our own addition, not a figure from the publisher. Three entries are tied to a quest: the Ananta Card requires "Divine Favors", the Kotokaze Card requires "The Ruby Bazaar", the Fat Chocobo Card requires "Heading Towards the Showdown".

Two hiccups in the official pages

The first is a typo, and it concerns the name of the reward. In the Mog Mog Challenge block, the French site writes: "you will obtain a lot of unusual Memory Crystals and 5 holdings of col uolon". "Col" instead of "cor" — the rest of the page, including the rewards table, correctly writes cor uolon [Uolon Horn]. This mistake belongs to the publisher, not to us; we are flagging it rather than silently correcting it, since searching for "col uolon" will return nothing in-game.

The second concerns the name of the currency. The same footnote appears on both official French pages, word for word — except for the item name. The Lodestone announcement speaks of "unusual Memory Crystals of Astronomy I", the special site of "unusual Allagan Memory Crystals", and the rewards table of "Unusual Astronomy I Memory Crystal". Three different phrasings on the same day; we are going with the one from the exchange table, the only one that matches an actual item label. On that same page, the rewards blurb also writes "in exchange exchange" and pluralizes it as "holdings of cor uolons".

In practice

Tracking goes through the Mog Mog Guide, to be claimed from the Traveling Mog and then stored in your Precious Items. The site shows three meeting points — Limsa Lominsa - Lower Decks, New Gridania and Ul'dah - Steps of Nald — without publishing coordinates.

Payouts are not uniform: rewards from regular content arrive "automatically", while those from the weekly content and the two challenges require clicking the "Claim" button in the Mog Mog Guide. An unclaimed holding is not an acquired holding — forgetting costs a week on a calendar that only offers one week of leeway.

Two deadlines remain, and they should not be confused. "Starting with update 8.05, it will no longer be possible to claim your rewards via the Mog Mog Guide"; "Item exchange will be available until update 8.1". The first shuts off the flow of rewards, the second closes the shop, and the publisher has not dated either one. Only one date truly matters for the Uolon Horn: Tuesday, September 22, 2026 at 10:00 AM.